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Hi all, I just bought a 2001 HB with 166000 miles on it. The engine and transmission were rebuilt and beefed up a couple years ago and the guy I bought I from did little to no maintenance on it. This is my first C5, the last two Corvettes I owned were C4's. I have been reading through the forums here and working to diagnose and fix the codes/issues. Following other threads I have replaced both front Hub Assemblies and the RF Speed sensor harness. The hubs were sounding rough so they needed to go anyway. The car came equipped with the F45 suspension but has non-magnetic shocks, so I also installed bypass modules. I've checked all of the wiring I can and it all seems ok. I have cleared all existing codes and some are constant. I'm going out of my mind trying to get these codes clear. Any help will be greatly appreciated.
My current codes are:
C1233 RF Wheel Speed Circuit open or shorted
C0620 Suspension position sensor circuit
C0695 Position Sensor over current
C0583 Suspension Actuator circuit high
B2607 Seat horizontal position sensor
Thanks,
David
Last edited by CorvetteBrewer; May 20, 2019 at 10:54 PM.
Reason: Spelling
So after continuously trying the fixes on the forums I decided to look further into the wiring. Turns out the RF wire harness was cut/worn through near the balancer. So I cleaned, trimmed, soldered together, and heat shrink tubed all of the wires. Started the car and no codes! Felt great until I took it for a ride. At 30-50 mph the Service Traction Control and Service ABS warnings will display on the DIC, and the ABS light will illuminate. Once I shut the car off the DIC shows clear and the only code is C1233H. going crazy again trying to figure this out.
Any help or suggestions are welcome and greatly appreciated.
So after continuously trying the fixes on the forums I decided to look further into the wiring. Turns out the RF wire harness was cut/worn through near the balancer. So I cleaned, trimmed, soldered together, and heat shrink tubed all of the wires. Started the car and no codes! Felt great until I took it for a ride. At 30-50 mph the Service Traction Control and Service ABS warnings will display on the DIC, and the ABS light will illuminate. Once I shut the car off the DIC shows clear and the only code is C1233H. going crazy again trying to figure this out.
Any help or suggestions are welcome and greatly appreciated.
David
Turn the ignition switch ON (engine OFF)
Clear the messages in the DIC using the reset button and then read the DTCs in the same ignition cycle.
Post ALL of those DTCs.in ALL of the modules!
might check the wire connector where the wheel sensor plugs into the wire harness. the female side of gm's connectors are not very good and they tend to open up and not allow the male side to make a good connection.
best way to check is to take a male connector out of the plastic housing so you can plug it in the female side and see how snug the connection is.
First I'd disconnect the wheel speed connector and see if the sensor reads between 850-1350 Ohms. The sensor produces an AC signal so if you spin the wheel you should see MORE than 100Mv !!....with the 1233 "short or open" I'd disconnect the ECBM harness and see if you have a short to ground or voltage, an open, or the wires are shorted together...check the connections at the EBCM too !!...this is wiring for an '01 !!
After having not driven the car
I turned on the ignition switch (engine off)
There were no messages to clear on the DIC
Here are all of the modules and codes found:
10-PCM NO CODES
28-TCS NO CODES
38-RTD NO CODES
40-BCM NO CODES
58-SDM NO CODES
60-IPC NO CODES
80-RADIO NO COMM.
99-HVAC NO CODES
A0-LDCM NO CODES
A1-RDCM NO CODES
A6-SCM B2607 H
B0-RFA NO CODES
Here are the codes after driving the car, shutting it down for 5 minutes:
I turned on the ignition switch (engine off)
There were no messages to clear on the DIC
10-PCM NO CODES
28-TCS C1233 H
38-RTD NO CODES
40-BCM NO CODES
58-SDM NO CODES
60-IPC NO CODES
80-RADIO NO COMM.
99-HVAC B0361 H C
A0-LDCM NO CODES
A1-RDCM NO CODES
A6-SCM B2607 H
B0-RFA NO CODES
As before the DIC starts flashing Service Indicators at approximately 30 mph.
The harness is new but as per your suggestion I pulled the plug and checked the female connector side with a male connector I extracted from an old harness. The fit is snug.
I re-metered the RF WSS and it shows 1111 ohms.
The AC signal is reading 450Mv when I spin the rotor as fast as I can by hand.
The ECBM wiring looks good and intact, I'll have to pull the harness connector and try to work through the diagram you provided. I must admit that I'm not awesome at electrical and that may take some time.
Everything looks like it's good electrically (sensor and wiring) but I would still look at those wires at the EBCM end....just may be a crappy intermittent connection there...if the computer sees a bad signal for only .02 seconds the DTC sets !!...unfortunately a regular old multimeter is too slow to see this change....you would need to have an oscilloscope hooked up to the wheel sensor driving at 30-50 MPH to see this rapid change in voltage...a graphing multimeter may work !!
Were you checking the WSS voltage using AC volts or DC volts setting on the meter. I remember testing mine and I was getting well over 1 volt but it was on the AC scale..
You can disconnect the connector at the EBTCM and test the WSS and wiring, resistance and voltages all the way up to that point.
I was checking the WSS in AC mode on my tester. Should I have been testing on DC?
It's looking like I'm going to have to find someone with a GM Tech 2 to help me diagnose the issue. Since its a front wheel I'm having a hard time getting the wheel to go fast enough to see a drop in signal as if I'm traveling at 35mph. Even a graphing multimeter seems like it would be hard to replicate the issue with out being on the road and I'm trying to keep my budget down by not having to purchase $1000+ in tools.
Short of buying the remote hookup style Snap-on Verus, what would you recommend to help diagnose this issue? I can pull the ECBM connector, check continuity, and voltage but I don't know how to spin the front wheel fast enough.
I truly appreciate Y'all helping me with this! That's why I had to buy another Vette, the people that love them are some of the best in the world!
I'm thinking and that can be very dangerous is that you have excessive "AC" ripple in your charging system affecting the "AC" wheel speed sensor AC voltage...with your volt meter hooked up to the battery set your scale to Volts AC and read the voltage...anything over 200 Mv is concerning....readings from the B+ post at the alternator to alternator case ground tend to be higher but try both !!...try your reading at idle and then maybe 2000 RPM...just an educated guess !!
Go to the EBTCM connector and read both front wheel signals there … Compare the LEFT to the RIGHT sensor voltages and see if they are similar. I remember seeing a lot more AC voltage using a simple multimeter.
Now I'm really thinking.....so you repaired some wiring near the HB...correct ??....when you repaired the wiring did the 2 wires look like this before you put on the heat shrink tubing...the wires are what we call "twisted pair"...on the C5 a MINIMUM of 9 turns per foot...did you twist the wires...see the symbol across the wires ??...a
twisted pair !!...oh, and I believe the wire is special also !!....was just a short length of wire repaired ??
C5 Diag I think you are onto something! The wires had come untwisted when cut/severed. I didn't twist them back as it never occurred to me that it would mater. Now that I think about it, it makes perfect sense. The wires need to be twisted to improve conductivity and reduce electromagnetic interference. Hence at low speed/ voltage signal the WSS data can reach the EBCM correctly lacking the twist, but increasing speed/voltage would cause additional interference and the wires won't be able to conduct the signal properly as there are gaps without the twist. The wires are long enough to not need an extension but I'm not looking forward to re-soldering them while twisted.
It will be a few days before I get another chance to work on the car but as soon as I do I'll let y'all know how it goes.
I wasn't sure how much of the wiring was damaged or if you spliced a new section in but I thought I'd ask. You are 100% correct about why those wires are twisted. Excess AC ripple can cause this and can also "whig out" modules and sensors or anything in the car that uses AC like the WSS's. The car battery acts like a big capacitor to smooth out that ripple...anytime you think you make have MAF,MAP,TPS sensor issues ALWAYS a good idea to check for this...let us know how much of the wiring untwisted and if this fixes the problem.
Update! Help needed
